This project is an observational study of a large urban clinic population of cerebral palsy patients. The population to be examined consists of approximately 1,000 Cerebral Palsy patients of the Hospital for Special Surgery in New York City. Staff of OBE collaborated on the definition of the standardized vocabulary, designed the data collection protocols and established a quality control mechanism for data collection. The results of the initial pilot phase for data collection necessitated major revisions in the data collection protocol with a greater emphasis in the surgical area. A second data collection pilot is in progress.